An 8-mm atrophic edentulous mandible in a frail patient on clopidogrel
A 74-year-old edentulous woman is brought to the emergency department after a fall at home. CT shows a 3-mm displaced fracture of the right mandibular angle and an undisplaced fracture of the left parasymphysis; the mandible measures 8 mm in height at the symphysis. She has not worn dentures for four years. Her history includes type 2 diabetes (HbA1c 8.4%), hypertension and a drug-eluting coronary stent placed eight months ago, for which she takes clopidogrel 75 mg daily. Her BMI is 17, albumin 30 g/L; she lives alone with no family nearby, and a daughter who is her documented healthcare proxy lives 600 km away. She is oriented but has mild cognitive impairment and cannot reliably follow a soft-diet instruction. There is no pre-existing denture to convert into a Gunning splint, and the on-call team proposes circummandibular wiring with a soft diet.
1. Compare closed treatment with open reduction in this patient and justify your recommendation.
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The decisive variables are bone height (8 mm), edentulous state with no denture or splint available, two fractures, systemic comorbidity and inability to comply with a soft diet.
Against closed treatment. In an atrophic mandible the bone depends largely on periosteal and not medullary blood supply, and the contact area at the fracture ends is tiny. Closed reduction relies on a splint or wiring system to hold a reduced position; with no denture, no Gunning splint, and circummandibular wires that cannot control a two-fracture mandible, the construct is mechanically inadequate. Combined with a patient who cannot maintain a soft diet and is cognitively impaired, the predictable outcomes are non-union, malunion, plate-free fibrous union and further surgery in a frail patient. Circummandibular wiring in 8 mm of bone also risks damage to the inferior alveolar nerve and to the thin inferior border.
For open reduction. Open reduction with a load-bearing reconstruction plate restores contour immediately, allows early function and avoids dependence on patient compliance - which matters more in a patient living alone with cognitive impairment than in a fit 30-year-old. The evidence in atrophic edentulous mandible fractures favours open reduction and internal fixation with a load-bearing plate for union and function.
But be honest about the trade-offs. Open surgery means a general anaesthetic in a diabetic patient with recent coronary stenting, a 4–5 cm skin incision, and a wound over a thin atrophic border. The recommendation is therefore conditional: proceed to open reduction with a load-bearing plate provided the medical work-up supports anaesthesia and the clopidogrel question is settled. If anaesthesia is judged prohibitive, a closed approach with a custom splint and a feeding plan is the fallback - but it must be a planned fallback, not a default.
2. Assuming open reduction, describe the fixation strategy and how you would avoid nerve injury and hardware failure in 8 mm of bone.
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Plate choice. Use a load-bearing 2.4- or 2.7-mm locking reconstruction plate that spans both fractures and bridges them, so that masticatory load is carried by the plate rather than by the bone. A single load-sharing miniplate, or two miniplates, is inadequate here: with 8 mm of height there is not enough sound cortex above the canal for a tension band, and the plate will fatigue. Locking screws create a stable internal fixator and reduce the risk of screw loosening in osteopenic bone.
Screw configuration. At least three, preferably four, screws per fragment on each side of each fracture, with the plate adapted to the inferior border to maximise available bone. Bicortical screws give better purchase in atrophic bone, but only where the canal anatomy permits; over the mental nerve, stay monocortical and superior to the plate plane.
Access and nerve protection. An extraoral submandibular (Risdon) approach gives direct visualisation of the inferior border and mental nerve, which a transoral approach cannot match for a plate this long. Identify and protect the mental nerve at its emergence; in severe atrophy it may sit at or above the superior border. Keep dissection subperiosteal and preserve periosteum away from the fracture to protect the tenuous blood supply.
Grafting. If there is comminution, a gap greater than about 5 mm, or a revision of non-union, add an autogenous corticocancellous graft - but grafting alone never compensates for inadequate fixation. In this acute, minimally displaced injury, primary plating without graft is reasonable.
Post-operative. Radiographs at 6 weeks and 3 months, soft diet for 6 weeks despite the load-bearing construct, and explicit review for plate exposure, which is common in atrophic mandibles with thin mucosa.
3. How do you manage the clopidogrel, the diabetes, the nutrition and the consent process before and after surgery?
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Clopidogrel. She has a drug-eluting stent at eight months, so she is likely still within the mandatory duration of antiplatelet therapy; stopping it unilaterally risks stent thrombosis, which is catastrophic and much worse than a surgical bleed. The default position is to continue clopidogrel and manage bleeding locally with meticulous haemostasis, a drain where appropriate and tranexamic acid. If the anaesthetist insists on stopping it, that decision must be made jointly with cardiology and documented; do not let a surgical preference overrule a cardiology prescription in the anaesthetic room.
Diabetes. HbA1c 8.4% predicts impaired healing and infection. Aim for perioperative glucose control with a documented plan, avoid sliding-scale-only management, and treat any wound infection aggressively. Do not delay an unstable fracture indefinitely for glycaemic perfection, but do not operate on a patient in ketoacidosis.
Nutrition. BMI 17 with albumin 30 g/L and living alone is a genuine risk factor for non-union and wound breakdown. Dietitian referral before discharge, high-calorie high-protein oral supplements, and a plan that does not depend on her remembering instructions - for example a delivery service and a district nurse visit. Consider a short period of nasogastric or supplemental feeding only if oral intake is impossible.
Consent. She has mild cognitive impairment, so assess capacity specifically for this decision; if she lacks it, the daughter as documented proxy must be contacted by telephone with a witness and the discussion recorded, and the treating team must act in her best interests if the proxy cannot be reached in an emergency. Discuss non-union, plate exposure, infection, nerve injury, anaesthetic risk and the alternative of conservative treatment. Record that the daughter was involved. The medico-legal risk here lies in proceeding without documenting the capacity assessment and the proxy conversation, not in the surgery itself.